I attempted to use styrene at 1/8″ thickness but it was too flimsy. You can try using 1/4″ thick wood. Its somewhat easy to cut. If you want something strong, try lexan/ polycarbonate plastic. Which can be hard to cut, if you don’t have the right tools. You can order plastics online like http://tapplastics.com/ with cut to size. Or you could try like home depot. or hobby stores. Anyways, thanks for taking interest and good luck in your mods.

One more question, Im having trouble remove the grey parts with the rod around the chamber of each gun. Any tips and if they snap is that okay because I don’t need them correct? And any other cheaper material that you think might work?

It takes 2 Nerf Mavericks to make one double barrel. The cheapest mavericks i could find is about $10 – $12 each plus tax. Plus the parts and materials I use are very tough so they dont break if you drop the gun. In the end, i really don’t make much out of making the guns. The price you see at the web is actually the lowest it can be. Any lower then i would be giving away free double barrel mavericks.